The Gochang, Hwasun and Ganghwa Dolmen Sites are locations for hundreds of dolmens used as graves and for ritual ceremonies. Most of these megalithic structures are dating from the period of the first millennium BCE. According to specialists, Korea contains more than 40% of the world's dolmen.

The site located on Gangwha Island is the easier most convenient one to visit from Seoul. From the Sinchon bus Terminal, take a bus to get to Gangwha Island bus terminal in one and a half hour and from there, take another bus to move on the island. However, the dolmen are scattered throughout the island and it is difficult to see most of them and to have a general view.

A notable dolmen on Ganghwa Island's site is a kind of table-type dolmen where it was believed ancestral rites were performed. This dolmen is thought to be the biggest in Korea.